How to tell if rings are bad on engine w/out heads

[Txtriathlete]

Not sure how to word this, hope this is clear. I have a new to me 82 with a 350. Smokes a bit on start up but then clears up, and has lots of historical "residue" leaked oil on the sides of the block below the heads. PO says "it used oil" but that's about all I know. It has sat off and on for many years not being driven regularly.

The leaks on the block look like they are coming from the head gasket. I feel like the start up smoke is likely valve seals or leakage from the head gasket. Engine has good compression and pulls hard. My plan is to pull the heads, redo the valve seals, lap the valves and replace the head gaskets.

I feel like the rings are good (little smoke on start, good power and compression) but really don't want to do heads twice if the rings are bad. So, any way to check rings while the engine is apart?

 

[Ricko1966]

A few things that come to mind. Why not run a leak down test before pull the heads?Why not do a wet/dry compression test before you pull the heads? I suppose if it were mine and couldn't do the above for whatever reason I'd pour oil to a measured depth say 3/4 inch in each cylinder and observe how fast they all seep down,you'd be looking for uniformity . 1 leaks off in 10 minutes the other 7 take 20 minutes I'd be concerned. But honestly if it were mine,and didnt have much ridge,I'd take the heads in for a 3 angle valve job,while the heads were at the machine shop I'd do rings,rod bearings,oil pump,and a timing set. Then I'd have an engine I could trust to not have issues for a long time,for not much money.
This is almost always my go to an if the heads off something. I don't want to put heads on something that's going to use oil,lose oil pressure, lose a rod bearing in a year or need a timing chain in a year.

 

[Txtriathlete]

A few things that come to mind. Why not run a leak down test before pull the heads?Why not do a wet/dry compression test before you pull the heads? I suppose if it were mine and couldn't do the above for whatever reason I'd pour oil to a measured depth say 3/4 inch in each cylinder and observe how fast they all seep down,you'd be looking for uniformity . 1 leaks off in 10 minutes the other 7 take 20 minutes I'd be concerned. But honestly if it were mine,and didnt have much ridge,I'd take the heads in for a 3 angle valve job,while the heads were at the machine shop I'd do rings,rod bearings,oil pump,and a timing set. Then I'd have an engine I could trust to not have issues for a long time,for not much money.
This is almost always my go to an if the heads off something. I don't want to put heads on something that's going to use oil,lose oil pressure, lose a rod bearing in a year or need a timing chain in a year.

I could do the oil seep test, that's a good idea. Compression is good now and leak down would be compromised by blown gasket I think. I was trying to avoid pulling the engine, mainly for $ and shop space reasons, but I may have to suck it up and do it. Not sure I'm not gonna trust myself with rings and bearings tho so that will have to get sent off somewhere. Good ideas here, thanks.

 

[fast 99]

If outer edges of pistons are clean without carbon build up rings are worn. Suggests replacement would be warranted.

 

[Ricko1966]

Depends on what it's in but I've done lots of rod bearings,rings,and oil pumps laying on my back with the pan off. Not as easy but not real bad especially if you can have somebody topside and you underneath.

 

[MrHorsepowerLSx]

You could pull the pistons out and inspect them and the rings and look for any foul play…. I.E. a crack in a piston/ring, misaligned rings (causing oil and compression to get by) problem with the oil control rings. You could also take the rings off the pistons and set them in the bore about an inch down using the piston face (piston installed upside down) to square the ring the up, and measure with a feeler gauge the ring end gaps. That right there will help you discern if you have excessive cylinder wall wear or fatigue in the rings. As for the heads you can get an idea of how warm the valves are by simply spraying brake clean in the intake/exhaust ports and look at the combustion chamber to see if and how fast any fluid is escaping past the valve face. You could use water if needed or even motor oil, whatever you fancy. But if you use water blow out any excess after the test.

 

[peats]

I think your engine only needs valve cover gaskets and possibly valve seals. I would not remove the heads until i changed those two items.

 

[Craig Nedrow]

Time and money, never enough, but I agree with John, (peats), above. I would do valve gaskets, check the lifter clearance, (1/2-3/4 turn down from zero lash,) drive it. Probably four hours including the engine clean up. I hate to work on a dirty engine. The reason I am saying this, is to change the seals, you will need some specialized tools, (Valve spring compressor, spark plug air fitting to keep the valve from dropping.) Compression, or leak down are good, but are somewhat time consuming, but will give you a comprehensive evaluation of engine condition.